Zhoukoudian Locality 1
Both Layer 10, the lowermost archaeological horizon roughly dated to between 400,000 to 600,000 years ago, and the thick accumulations of the younger Layer 4 exhibited certain phenomena to suggest the use of fire by the initial excavators. In Layer 10 the evidence included: the presence of burned bones associated with flaked artifacts of quartz; a charcoal- and organic-rich layer at the base of the Layer; a lenticular zone of yellow and red clay overlying the organic-rich ones. In Layer 4, which is significantly younger than Layer 10 (ca. 250,000 to 300,000 years old), the evidence for fire included: Four to six meters of tan, powdery deposits, alleged to be ashes derived from fires; bright red colors; and the presence of three horizons with quartzite artifacts at the base of Layer 4.
In 1996 and 1997 trips were made to the site to collect samples for micromorphological and mineralogical analysis, the latter conducted by S. Weiner using Fourier Transform Infrared Spectrometry (FTIR).
The established profile of Layer 10 consists of bedded red, yellow, and dark brown silty layers, with rock fragments, and burned and unburned bone. The evidence of fire from this layer consists of bands of dark, silty material overlain by and laterally continuous with red and yellow silt (interpreted as in situ hearths) in the lower portion of the layer, so-called ash deposits in the upper portion, and blackened, possibly burned, bones found primarily in the uppermost part of the layer.
Micromorphological study of thin sections of these putative hearths showed that these features (Photo 1a and 1b) actually consisted of finely laminated silt and clay interbedded with reddish brown and yellow brown fragments of organic matter, limestone fragments, and dark brown, laminated silt, clay, and organic matter. No evidence of wood ash - essentially calcium carbonate - or pieces of charcoal were identified.
Thus on the basis of the composition as well as the bedded to finely laminated nature of the constituents, we concluded that the sediments were not due to in situ burning activity, but rather to deposition of clays and redeposited organic matter (some possibly burnt) in standing or slow-flowing water. Furthermore, in other parts of the Layer we found no other evidence for burning or wood ash, but rather micaceous silty clay with sand- and granular-size clasts of quartz, bone, redeposited aggregates of clay, mm-size clasts of limestone, and fragments carnivore excrements, presumably from hyaenas, which frequented the cave.
Layer 10 in the field
Layer 4 in the field